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• Asynchronous programming - A multithreaded model that’s most applicable to networking and communications
• Asynchronous programming - is a non-blocking architecture
• Multiple related operations can run concurrently without waiting for other tasks to complete.
• Non-blocking architecture - it doesn’t stop further executions while one or more operations are in progress.
• Async is multi-threaded, which means operations and programs run in parallel
• Async is non-blocking, which means it can send multiple requests to a server
• Sync is single-threaded in which one operation or program will run at a time
• Sync is blocking, as it can only send the server one request at a time and will wait for the request to be answered by the server
• Async increases the throughput in which multiple operations can run at the same time
• Sync is slower and more methodical
• Async programming is ideal for development projects with large iterations because it doesn't follow a sequence. It keeps the development moving forward.
• When to use async?

  ● Used in programming independent tasks.

  ● Responsive UI.
• Async offers advantages for users because it enhances their experience by decreasing the lag time and waiting time. This translates to faster, more seamless flows.
• Sync offers advantages for developers because it is simple and easier to code. It is also well-supported by all programming languages as the default programming method. No learning curve for sync programming.
• In Flutter, we need asynchronous code to fetch data over a network, write in a database, or read from a file
• Asynchronous computations usually provide a Future as a result.
• Dart use the async and await keywords.
• Future is a result of an asynchronous computation.
• Two states of future:

  • Uncompleted
  • Completed.
• Uncompleted - Calling an asynchronous function returns this future. This future waits for the function’s asynchronous operation to finish or throw an error.
• Completed - Asynchronous operation succeeds, the future terminates with a value
• Future syntax in Dart:

  Future<T>, T can be of any data type or void.
• A Future<T> instance produces a value of type T. If a future doesn’t produce any usable value, then the future’s type is void
• If asynchronous operation performed by the function fails for any reason, the future is completed with an error.
• To define an async function, add async before the function body.
• Await keyword works only in async functions
• State - an information that can be read when the widget is built and changed over a lifetime of the app
• setState() - allows us to set the properties of the state object that triggers the redraw of the UI
• State of an app is everything that exist in memory when the app is running. This includes the app’s assets, variables, UI, animation state, textures, and fonts.
• State management - the most popular and necessary processes in the lifecycle of an application
• Flutter is declarative
• Flutter builds its user interface to reflect the current state of your application
• Types of Conceptual States

  • Ephemeral State
  • App State
• Ephemeral State - the UI state or local state. It is the state you can neatly contain in a single widget
• Ephemeral State - No need to use state management techniques on this kind of state just use a StatefulWidget and the method Setstate().
• App State - This is when you want to share across many parts of your app. It is also called a shared state.
• There is also no clear-cut, universal rule to distinguish whether a particular variable is ephemeral or app state.
• Provider package - an easy-to-use package that wraps around InheritedWidgets that makes it easier to use and manage.
• Provider package - Widget listens to changes in the state and update it as soon as they are notified
• Types of Provider:

  • Listenable Provider
  • Change Notifier Provider
  • Value Listenable Provider
  • Stream Provider
  • Future Provider